man get_align_matrix () - Rotates a matrix to align it along specified coordinate vectors. Allegro game programming library.
NAME
get_align_matrix - Rotates a matrix to align it along specified coordinate vectors. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
void get_align_matrix(MATRIX *m, fixed xfront, yfront, zfront, fixed xup, fixed yup, fixed zup);
DESCRIPTION
Rotates a matrix so that it is aligned along the specified coordinate vectors (they need not be normalized or perpendicular, but the up and front must not be equal). A front vector of 0,0,-1 and up vector of 0,1,0 will return the identity matrix.